| | Upper Lake, CA | Highland, CA | United States |
| Population | 1,377 | 56,733 | 329,725,481 |
| Female Population | 48.7% | 50.0% | 50.5% |
| Male Population | 51.3% | 50.0% | 49.5% |
| Median Age | 47.6 | 32.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,213 | 53,214 | 309,327,143 |
| Population - 2000 | 989 | 44,605 | 285,036,114 |
| Population - 1990 | 941 | 34,439 | 251,960,433 |
| Pop. 2000 to Now | -2.2% | 24.9% | 15.6% |
| Pop. 1990 to Now | 2.8% | 61.7% | 30.8% |
| space4 | | | |
| Population Density | 818.7 | 3,026.1 | 93.4 |
| Land Area | 1.7 | 18.7 | 3,531,905.4 |
| Water Area | 0.0 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Upper Lake, CA | Highland, CA | United States |
| Age 0 to 4 | 4.6% | 7.2% | 5.9% |
| Age 5 to 9 | 1.8% | 8.5% | 6.1% |
| Age 10 to 14 | 3.8% | 9.2% | 6.6% |
| Age 15 to 17 | 0.0% | 4.4% | 3.9% |
| Age 18 to 20 | 1.6% | 4.7% | 4.0% |
| Age 21 to 24 | 3.6% | 5.4% | 5.2% |
| Age 25 to 34 | 11.8% | 13.7% | 13.8% |
| Age 35 to 44 | 20.8% | 13.2% | 12.9% |
| Age 45 to 54 | 23.6% | 12.9% | 12.6% |
| Age 55 to 59 | 10.2% | 5.9% | 6.7% |
| Age 60 to 64 | 7.8% | 4.6% | 6.3% |
| Age 65 to 74 | 2.5% | 6.0% | 9.6% |
| Age 75 to 84 | 6.0% | 3.3% | 4.5% |
| Age 85 and over | 1.7% | 1.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Upper Lake, CA | Highland, CA | United States |
| White | 88.9% | 24.0% | 59.4% |
| Black | 0.9% | 6.2% | 12.2% |
| Asian | 0.0% | 7.9% | 5.6% |
| Native American | 0.0% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.2% | 0.2% |
| Other | 0.0% | 0.5% | 0.4% |
| Two or More Races | 2.7% | 2.6% | 3.2% |
| Hispanic | 7.5% | 58.5% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Upper Lake, CA | Highland, CA | United States |
| Married Population | 45.4% | 47.6% | 49.8% |
| Currently Married | 44.0% | 45.9% | 48.0% |
| Married but Separated | 1.4% | 1.7% | 1.8% |
| Single Population | 54.6% | 52.4% | 50.2% |
| Never Married | 37.7% | 37.7% | 33.8% |
| Divorced | 16.0% | 9.9% | 10.8% |
| Widowed | 0.9% | 4.8% | 5.6% |
| space5 | | | |
| Household Size | 2.68 | 3.42 | 2.60 |
| Households | 507 | 16,532 | 124,010,992 |
| Family Households | 225 | 13,278 | 80,755,759 |
| Married couple, w/children | 25.3% | 33.6% | 30.5% |
| Married couple, no children | 55.1% | 30.4% | 42.9% |
| Non Family Households | 282 | 3,254 | 43,255,233 |
| Single householder, w/children | 19.6% | 23.3% | 15.8% |
| Single householder, no children | 0.0% | 12.8% | 10.8% |